The present invention is related to a card-type anti-miss/anti-theft alarm device including a portable mainframe and an alarm sub-frame. The alarm sub-frame is designed as a thin card with a dimension smaller than or equal to that of an existent credit card, whereby the alarm sub-frame can be easily placed and hidden in a small-size article carried with a user, such as a wallet, a suitcase, a portable computer, etc. In case the user misses the article or the article is stolen by a thief and spaced from the user by a certain distance, an alarm is emitted to warn the user.
It often takes place that a person misses a portable article or even a kid in a hurry. In order to solve this problem, a portable detection alarm has been developed. Such detection alarm includes a tracing transmitter and a cooperative receiving alarm. The transmitter continuously transmits intermittent a signal of a certain frequency for the receiving alarm to receive. In case the transmitter is spaced from the receiving alarm by a distance exceeding the monitoring range and the receiving alarm can hardly receive the signal, an internal alarm is driven to emit an alarm. In use, the tracing transmitter and the receiving alarm are respectively placed in a user and a portable article or a kid. The activation of the alarm is determined by whether the distance between the tracing transmitter and the receiving alarm exceeds the preset distance. The alarm is able to prevent the user from missing the article or the kid.
However, the tracing transmitter and the receiving alarm of the above portable detection alarm have large volumes so that it is inconvenient to carry such alarm device and the alarm device can be hardly well hidden. Also, the application of such detection alarm is quite limited. Such detection alarm is only applicable to specific large-size article and is easy to be found a thief. As a result, the thief can easily disassemble the alarm and make the user hard to locate the article.